Islamabad: A Pakistani researcher based at an Italian university has developed a low-cost solar-powered plasma water treatment system capable of removing toxic chemicals, antibiotic residues, antimicrobial-resistant bacteria and a wide range of emerging contaminants from wastewater, offering what experts believe could become an affordable solution to Pakistan’s growing water scarcity and industrial pollution crisis.
Developed by Dr Mubashir Saleem, a graduate of NED University of Engineering and Technology, Karachi, and a researcher at the University of Padua, Italy, the “SolarPlas” system uses non-thermal plasma technology to treat contaminated wastewater without adding treatment chemicals. Designed to operate using solar or wind energy, the system is virtually energy-neutral and provides advanced water treatment in a single compact process.
Dr Saleem said Pakistan, particularly Karachi, was facing an increasingly severe water crisis while industrial effluents and untreated sewage continued to contaminate rivers, drains and coastal waters.
“Our coastline has been badly damaged by industrial discharge and untreated sewage. Fish are moving farther away from the coast because of pollution, forcing poor fishermen to travel into deeper waters where many inadvertently cross international maritime boundaries and are arrested,” he said.
He maintained that industries could recycle their wastewater using the new system instead of discharging untreated effluent into the sea, reducing environmental pollution while also lowering their freshwater consumption and operating costs.
Explaining the technology, Dr Saleem said the system generates non-thermal plasma, often described as the fourth state of matter, by applying high voltage to water. The plasma produces highly reactive species, including hydroxyl radicals and ozone, which rapidly break down organic pollutants, pharmaceutical residues and other persistent contaminants while simultaneously inactivating harmful microorganisms without requiring additional treatment chemicals.
He said one of the major advantages of SolarPlas was its ability to perform multiple treatment functions in a single step. Conventional wastewater treatment systems generally require three or four additional treatment stages to achieve comparable removal of emerging contaminants, effective disinfection and improved water quality. By integrating these functions into one compact process, SolarPlas offers a simpler, more cost-effective solution that is particularly suitable for decentralized and resource-limited settings.
According to Dr Saleem, conventional wastewater treatment technologies, many of which are based on designs developed decades ago, are generally not designed to completely remove emerging contaminants such as endocrine-disrupting chemicals (EDCs), hormone residues, pharmaceutical compounds, personal care product chemicals and other micropollutants.
These contaminants can persist in treated wastewater and enter rivers, groundwater and ultimately drinking water supplies, where even very low concentrations may interfere with biological systems. Scientific studies have linked some endocrine-disrupting compounds with hormonal disturbances, reproductive disorders, developmental abnormalities and adverse effects on both wildlife and human health.
He said laboratory testing of hospital wastewater showed that the SolarPlas system completely inactivated antibiotic-resistant bacteria and resistance genes under the tested conditions, while removing more than 95 percent of organic pollutants and reducing antibiotic residues by up to 99 percent.
The researcher noted that analyses of wastewater from Karachi’s Lyari River had detected significant concentrations of antibiotic residues and other emerging contaminants, raising concerns over the spread of antimicrobial resistance, environmental contamination and long-term risks to public health and aquatic ecosystems.
He urged policymakers to introduce modern wastewater treatment regulations and encourage the adoption of advanced treatment technologies capable of removing emerging contaminants that conventional systems often fail to eliminate.
Dr Saleem said the modular system could be scaled from a single household to large industrial facilities. A domestic unit is expected to cost between Rs300,000 and Rs500,000 (approximately €1,000 to €1,500) and could produce recycled water suitable for irrigation, gardening, vehicle washing and other non-potable uses. When integrated with a reverse osmosis (RO) unit, the treated water could also be made suitable for drinking, subject to compliance with applicable drinking water quality standards.
He said the technology was particularly suitable for water-stressed countries such as Pakistan, where recycling wastewater and reducing industrial pollution would become increasingly important as freshwater resources continue to decline.